Induction-transformer.



J. LAUFER.

INDUCTION TRANSFORMER.

APPLICATION FILED APR. 24, 1914.

1,199,086. Patented Sept. 26,1916.

UNITED STATES PATENT OFFTCE.

JULIUS LAUFER, Ol BERLIN, GERMANY, ASSIGNOR TO SIEMENS-SGHUCKERTWERKE,G. M. B. 1-1., 01? SIEMENSSTADT, NEAR BERLIN, GERMANY, A. CORPORATION OFGERMANY.

INDUCTION-TRANSFORMER.

Specification of Letters Patent.

Patented Sept. 26, 1916.

To all whom it may concern:

Be it known that I, JULIUS LAUFER, a German citizen, and resident ofBerlin, Germany, have invented certain new and useful Improvements inInduction-Transformers, of which the following is a specification.

My present invention relates to induction transformers, that is totransformers of the induction motor type, which consist of a fixedmember or stator and a rotary member or rotor, and which are adjusted bythe relative position of the stator and rotor for changing the relativephase values of the of the members of the induction transformer. Thisrush of current is furthermore fully brought to action by reason of thesmall reactance of the induction transformer. Upon the rotor of thetransformer therefore an exceedingly large torque will be exerted sothat the apparatus will have the tendency to act as an induction motorand to rotate with great force, which may cause either the rotor body tobecome loose, or a distortion or breaking of the rather long and thinrotor axle or other injuries to the adjusting mechanism for the rotor.

The object of my invention consists in providing means for protecting aninduction transformer against such injuries in that free rotation of therotor will be enabled in case a certain limit of torque is surpassed.For this purpose the rotor is coupled with the adjusting mechanism, forinstance by means of a slip coupling, which is so adjusted that thefriction between the two halves of the coupling will be overcome in caseof a torque which is exceeding a permissible value. As regards thelocation of the coupling between the rotor body and the looking oradjusting means it is unessential whether for instance the coupling isarranged between the rotor axle and the axle of the adjusting mechanism,or whether the rotor body is constructed to be rotatable upon the axleand a yielding coupling provided therebetween. The construction may bealso made in such a manner that the coupling will be disengaged in caseof the torque assuming an impermissible value. This disengaging ispreferably accomplished electrically in dependence from the rotorcurrent, and if the rotor body will be loosely mounted on the axle, thisdisengaging may be done by means of bolts which are electromagneticallyactuated from the rotor windings, said bolts being normally inengagement with the axle and coming out of engagement in case of a rushof current.

In the accompanying drawing I have shown an example of a constructionaccord ing to my present invention.

Figure l is an elevation of an induction transformer comprising aslip-coupling according to my present invention, Fig. 2 shows a modifieddevice for uncoupling the rotor from its axle by means of shear boltsand Fig. 3 represents a similar device for electro-magneticallydisengaging the rotor.

a is the stator of the induction transformer, b the rotor of the same, 0the slip rings, (Z the axle which is carried through the bearing amounted at the upper and a similar bearing at the lower end of thestator. The aforementioned slip-coupling is indicated at g. Theadjusting device for adjusting the rotor in different angular positionsis indicated by a worm gear h, 2', which may be operated by a crank orhand wheel or in any other desired manner. In Fig. 2 the coupling devicewhich may be substituted for the slip-coupling, comprises essentially abolt j which is passed through a borehole in the hub of the rotor body7) and the axle (Z, said bolt j being so dimensioned that it will beshorn off at a definite torque between the axle (Z and the rotor body7), thus permitting free rotation of the rotor body. Theelectro-magnetic means for dis en aging the coupling between the rotorand its axle, as shown in Fig. 3 consist of a pin or bolt 70 passingthrough a hole in the hub of the rotor and normally engaging the samewith its axle, which pin or bolt is drawn out by the solenoid Z whichmay be connected to the rotor windings. 7,

Having thus described my invention I claim as new and desire to secureby Letters Patent of the United States 1. In an induction transformerthe combination of a stator and a rotor, an adjusting mechanism foradjusting the position of said rotor relatively to said stator, andcoupling means intermediate between said adjusting mechanism and saidrotor, said coupling means being adapted to mechanically disengage saidrotor from said adjusting mechanism, if the torque exerted by said rotorsurpasses a certain maximum value.

2. In an induction transformer the combination of a stator and a rotor,an adjusting mechanism for adjusting the position of said rotor, and aslip-coupling adapted to disengage said rotor from said adj ustingmechanism, if the torque exerted by said rotor surpasses a certainmaximum value.

In witness whereof I have hereunto set my signature in the presence oftwo subscribing witnesses.

JULIUS LAUFER. Witnesses WVoLnnMAn HAUPT, HENRY H Asrnn.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

